1. Field of the Invention
The present invention relates to an object specifying device which specifies each of a plurality of objects existing in the forward area of a controlled vehicle as a control-based object when the vehicle should be controlled on the basis of the movement of the object and specifies each of the objects as an unnecessary object when it is not required to control the vehicle on the basis of the movement of the object. The present invention also relates to a vehicle control apparatus which controls the vehicle on the basis of movements of the control-based objects specified by the device while disregarding movements of the unnecessary objects specified by the device.
2. Description of Related Art
It is known that an object specifying device mounted in a controlled vehicle is used to prevent the controlled vehicle from colliding with an object or to control an inter-vehicle distance between the controlled vehicle and a forward vehicle, running in the forward area of the controlled vehicle, for the purpose of automatically running the controlled vehicle. This device specifies an object placed at the forward area of the controlled vehicle as a control-based object when the controlled vehicle should be controlled on the basis of the specified object.
Japanese Patent Specification No. 4210640, for example, discloses this device. In this Specification, the device mounted in the controlled vehicle detects a plurality of objects existing in the forward area of the controlled vehicle. Then, a judging area placed around the first detected object is set. When the second detected object has passed through this judging area, one of the first and second detected objects which has the lower speed or approaches the controlled vehicle is specified as an unnecessary object. That is, when the controlled vehicle is controlled according to movements of control-based objects, the device excludes the object specified as the unnecessary object from the group of control-based objects.
In this technique, for example, when the forward vehicle denoting one object has passed over a manhole, the device detects that the manhole denoting another object has passed through the judging area set around the forward vehicle. Then, the device specifies the manhole having the speed lower than the forward vehicle or approaching the controlled vehicle as an unnecessary object. Therefore, the device can exclude the manhole from the group of control-based objects.
However, during the running of the controlled vehicle and the forward vehicle on a straight road, the forward vehicle obstructs the view of a manhole placed on the road. Therefore, the device cannot detect the manhole until the forward vehicle passes through on or over the manhole. That is, there is a high probability that the device cannot detect the manhole until the manhole passes through the judging area of the forward vehicle. In this case, the device cannot detect that the manhole has passed through the judging area of the forward vehicle. As a result, there is a high probability that the device cannot specify the manhole as an unnecessary object.